sporopollenin

[ spawr-uh-pol-uh-nin ]
/ ˌspɔr əˈpɒl ə nɪn /

noun

an inert, tough polymer forming the resistant outer coat of a pollen grain or spore.

Scientific definitions for sporopollenin

sporopollenin
[ spôr′ə-pŏlə-nĭn ]

An organic polymer that is extremely resistant to degradation. Pollen grains and many kinds of spores have a protective outer coating of sporopollenin, which is so durable that microfossils of sporopollenin are found in rocks over 500 million years old.